Why Use Cast Iron for Butter-Basted Steak
DENVER CHEF JUSTIN BRUNSON SHARES THE KEY TO LIVE FIRE, CAST-IRON COOKING.
There are certain things in life that just go together. Eggs and bacon. Blue jeans and t-shirts. Dogs and humans. And, of course, campfires and a cast-iron pan. To Justin Brunson, this is a universal truth, learned over a lifetime of cooking meat over an open flame.
“My first live fire was with cast-iron pans over a campfire,” says the Denver chef. “There’s just something so primal and raw about it—almost romantic. The way the fat drips off and sends smoke back up onto what you’re cooking. There’s just this flavor that a good piece of meat with good salt makes over a hot fire. It’s truly the best bite of food.”
Brunson knows fire, and meat—the owner of protein-centric restaurants Old Major and Masterpiece Delicatessen before launching his own provisions brand, River Bear American Meats. He learned these loves as a kid growing up in Cedar Rapids, Iowa, where he spent weekends camping, hunting, and cooking game, like freshly harvested venison T-bones, both over coals and back home in cast-iron pans. Here, his grandmother’s Griswold was the holy grail, now part of his “small problem” today, aka a cast-iron collection of 30-plus pieces.
Brunson and Butter Pat founder and Dennis Powell, circa 2018.
“One of my youngest memories in the kitchen, I must’ve been 4 or 5, telling my grandmother that her fried chicken smelled better than roses,” he says with pride. “She taught me how to cook, and as she taught, she taught me what pans she used. She always cooked in cast iron. It’s always been part of my life and my cooking.”
But it was in his early 20s when he truly fell for live-fire cooking, incorporating it into his award-winning restaurants that helped put whole-animal butchery on the map. He now keeps a Cowboy Cauldron at the center of the outdoor kitchen in his backyard, relishing the ritual of building a fire in and of itself—the prep, the precision, the communal nature. That practice, like cooking in cast-iron, can be intimidating, but he recommends novice pyros just jump right in.
“Rip off the Band-Aid and go for it,” says Brunson. “Build a nice little fire, let it burn into coals, put your pan on top, and give it a shot. It’s like any other form of grilling—just a lot more fun.”
On top of that, there are temperatures that a live fire can reach that a home stove simply can’t, often exceeding 600 degrees Fahrenheit, which is where cast iron comes in. Instead of going from zero to 60 with such high heat, the metal provides slow-and-steady heat conduction across the pan’s surface, allowing for a more even distribution to the meat.
The key, says Brunson, is to first and foremost, get your pan nice and hot, but also be sure to cook with a high-temperature oil, like rice or grapeseed. Different oils have different smoke points, or the temperature at which it stops shimmering and starts burning—when the flavor of your food can take a turn for the worse.
“Don’t use olive oil because it’s got a low smoke point,” he says, noting an affinity for other fats like lard or tallow, too.
Another reason Brunson loves cast iron? Its ability to hold all of those good juices often sacrificed to the fire gods when cooking over a grill grate. (In other words, a travesty.)
“All that fat drips off and you only get the Maillard reaction”—or sear—"where the metal touches the meat,” says Brunson. “I’m also a butter-baste kid. It’s a technique everyone should learn how to do at home.”
Brunson at Hot Luck food festival in Austin, TX.
He starts by salting and peppering his steak, putting his pan over the direct heat, adding a high-temp oil, and when it begins to dance, pressing the meat into the pan’s surface. He flips it once, moves the entire operation to the cooler side of the fire, then adds a few knocks of butter, some sprigs of thyme and rosemary, and smashed garlic cloves—an ambrosial infusion to be spooned over the meat for about a minute until it finishes cooking.
“You want your butter to be yellow and foamy, never brown or burnt,” says Brunson. “Being a thick material and holding an even temperature, cast iron helps that butter stay nice and light. Then all of the milk solids will caramelize and make for the best crust ever”—in his expert opinion, the crux of any cooked piece of meat.
“There’s nothing better than a steak with a crispy, crunchy outside and a nice medium-rare, beautiful, juicy inside,” he says emphatically. “As a purist, I’m a big fan of the cast iron, because I really believe you get to taste more of the flavor of the meat.”
On both points, we can’t help but agree.
Like we said, eggs and bacon. Dogs and humans.
Cast-iron, campfire cooking.
About Justin Brunson
Find Brunson's Butter-Basted Steak recipe here.
From River Bear Meats:
Executive Chef Justin Brunson’s passion for quality ingredients and artfully designed cuisine stems from his agricultural roots earning him recognition as one of Denver’s most impressive and innovative chefs.
River Bear is the next evolution of charcuterie skills that Brunson has been honing his entire life. Meat is his passion, and he aims to make it yours as well.
Learn More About Justin at River Bear Meats